16/05/2005
NEWS STORY
Alan Permane, Chassis race engineer, Car 6
Monaco is a unique circuit in the season – both because of its unusually twisting layout, which places a real premium on slow-speed performance and mechanical grip, but also because of the nature of the track surface, which as well as being extremely slippery at the start of the weekend, is also very bumpy and sharply cambered. Indeed, to cope with this, we run the ride heights anywhere from 5 to 7 mm higher than normal.
Mechanically, we spring the cars softly to maximise the grip available to the drivers but also to cope with the bumps and cambers. The wheels must be able to move independently in order to cope with imperfections in the track surface, and we also soften the anti-roll bars in order to enable this. We also pay special attention to the camber of the front and rear wheels, running high angles – although too much camber can lead to instability in the bumpy high speed braking areas into Turn 1, or the harbour chicane, for example.
The tight Grand Hotel hairpin obliges us to revise steering geometry, as it requires more lock than any other corner of the season – for the entire circuit, we run up to twice as much steering lock as at our previous race in Barcelona. Indeed, the control systems have an extremely important role to play in the slower corners, controlling wheelspin on exit through the traction control, but also by running the diff a little freer than normal in order to help the drivers turn the car on the throttle.
The circuit also sees the highest downforce levels of the year used on the cars – to help braking and traction primarily, as most of the corners are too slow to enable a real gain from extra downforce levels. However, the increased stability provided by maximum downforce on the low grip surface is always of benefit to the lap time. Wing angles at front and rear are usually run at maximum levels although with the R25, we will be slightly below maximum downforce at the front.
For all the attention we pay to car set-up, though, our changes to the car are always very difficult to judge. The Monaco surface is very low grip, and not at all abrasive. It picks up grip all weekend, making lap-time improvements in practice hard to decipher, and the circuit – as well as the drivers – is constantly improving throughout the race. The very soft tyres lay down a lot of rubber on the racing line, and the fastest laps of the weekend often come in the race when grip levels are at their highest. Indeed, we often see ‘negative degradation' at Monaco, meaning the cars are getting quicker through their race stints as grip levels increase.
Last year's Renault was extremely competitive all weekend in Monaco, and the R25 represents a step forward in all areas – and is much more comfortable for the drivers on the limit. This could prove a key factor in Monaco, a circuit that Giancarlo loves. Coupled with the new aerodynamic package, this means we will certainly have our eyes on winning the race, and improving the team's championship position even further.
Fabrice Lom, Engine race engineer, Car 6
Monaco has the reputation of being the least demanding circuit of the season for engines, but that can be firmly categorised as an ‘urban myth'. People often consider it to be undemanding because the parameters by which the severity of a circuit is usually judged are less significant (the longest full throttle period lasts just 8 seconds, for example), the average speed is low and the race distance is the shortest of the season.
However, the apparent simplicity of the change is not an accurate picture of the demands Monaco places on the V10. The circuit is very tight, and extremely bumpy: this means over-revving is very common, and performance is required from unusually low engine speeds – the cars are running at just 45 kph through the Grand hairpin.
This means the engine must be as driveable as possible to be quick round Monaco. A shortfall in peak power will be less severely penalised at this circuit, and we approve the engine specification in the context of the unusual characteristics of the circuit on the dyno, simulating the low revs and hard acceleration. Monaco rewards a rounded engine more than the V10 which delivers the highest power: it needs to pull well from low revs, while successful integration into the chassis will assist in the mechanical grip and handling of the car.
The other challenge we face in making the engine last the distance is cooling. We run very closely-spaced gear ratios to maximise the car's acceleration, and this means the ratio between engine speed and car speed is higher than at a more normal circuit. The higher this ratio, the greater the risk is of overheating, and this is one of our major preoccupations at Monaco. However, we are helped by the fact that aerodynamic efficiency is less important than at other circuits on the calendar – which means we can open up the car's bodywork if necessary without paying a major lap-time penalty.